The present invention relates to a navigation instrument for roadway vehicles.
On scheduled roadway trips the vehicle is run at a desired speed to arrive at the destination on time. It is convenient for the vehicle driver to be constantly informed of the actual average speed of the vehicle over the distance travelled from the starting point of the trip. A known navigation meter or instrument for roadway applications are designed to compute the average speed of the vehicle constantly and indicate the computed speed. However, because of the varying traffic condition which the vehicle encounters during its trip, the average speed value also varies from instant to instant so that the vehicle driver has to constantly shift his attention to the meter. This is troublesome for the driver and sometimes undesirable for safety drive.